1. Technical Field
The present invention relates to a resonation device, an oscillator, an electronic apparatus, and a moving object.
2. Related Art
As a frequency generation source for supplying stable frequencies, crystal oscillators are widely utilized in clock signal sources and the like of broadcasting instruments, measuring instruments, and digital instruments. Particularly, in a crystal oscillator with heater (oven controlled xtal oscillator: hereinafter, referred to as the OCXO), a small-sized heater and a quartz crystal resonator are accommodated in a container and the ambient temperature of a resonation element is uniformly maintained so that highly favorable frequency stability is attained.
As an example of such an OCXO, JP-A-2010-288249 has proposed a resonation device (piezoelectric device) in which a heater (heater element) is provided directly under a resonation element (piezoelectric element) of which both ends are supported so that heat conduction to the outside of the container (package) can be prevented and the resonation element (piezoelectric element) can be heated while suppressing energy.
However, according to the resonation device disclosed in JP-A-2010-288249, a distance between attachment portions (base portions) for mounting the resonation element in the package is long. Therefore, due to the difference between heat expansion coefficients of the resonation element and the package, significant thermal stress is generated between the resonation element and the package during a heat processing step in the manufacture, thereby resulting in a disadvantage in that oscillation frequencies of the resonation device fluctuate.